Proper planning and proper selection of the laying method of photovoltaic cables is one of the important aspects of cable design.
When laying cables, consider the engineering conditions, environmental conditions and cable specifications, quantity and other factors, and select the appropriate laying method according to the requirements of reliable operation, easy maintenance and technical and economical rationality.
The laying of DC cables for photovoltaic power generation projects mainly includes direct laying of sand mats, laying of pipes, laying of trenches, laying of cable trenches, laying of tunnels, etc. The laying of AC cables is not much different from that of general power systems.
DC cables are mostly used between photovoltaic modules, between strings to DC combiner boxes, between combiners and inverters. The cross-sectional area is small and large. Generally, the cables are bundled along the component brackets or directly buried. Generally, when laying, consider:
(1) The connecting cable between the components and the connecting cable between the string and the combiner box, as far as possible, using the component bracket as the channel support and fixing of the cable laying, can reduce the influence of environmental factors to a certain extent.
(2) The force of cable laying should be uniform and appropriate, and should not be too tight. The temperature difference between day and night in photovoltaic places is large, and cable breakage should be avoided caused by thermal expansion and contraction.
(3) In the photovoltaic material cable lead on the surface of the building, the overall aesthetic appearance of the building should be considered. The laying position should avoid laying cables at the sharp corners of the wall and the bracket to avoid short circuit caused by cutting or grinding damage to the insulation layer, or cut by shearing force. The wire causes an open circuit. At the same time, it is necessary to consider the problem that the cable line is directly struck by lightning.
(4) Reasonably plan the cable laying route, reduce the crossover, and merge as much as possible to reduce the amount of earthwork excavation and cable usage during the construction of the project.